A student took four test tubes I, II, III and IV containing aluminium sulphate, copper sulphate, ferrous sulphate and zinc sulphate solutions, respectively. He placed an iron strip in each of them. In which test tube, a brown deposit is formed?

A student took four test tubes I, II, III and IV containing aluminium

1.	A student took four test tubes I, II, III and IV containing aluminium sulphate, copper sulphate, ferrous sulphate and zinc sulphate solutions, respectively. He placed an iron strip in each of them. In which test tube, a brown deposit is formed?
Answer» Solution : A brown DEPOSIT is formed in TEST tube II because iron being less reactive does not displace metals from the solution of `Al_(2)(SO_(4))_(3),FeSO_(4)` and `ZnSO_(4)`but it is more reactive than Cu. So, it displaces COPPER from `CuSO_(4)` and forms `FeSO_(4)` which is GREEN in colour and a brown deposit of copper metal.